Don't confuse the BP oil spill with the future of natural gas. The fuel is expected to be a global contender when it comes to reducing greenhouse gas emissions from power plants through 2050.

That's the conclusion of an MIT study group, which says that natural gas will erode coal's market share over time and particularly after domestic and international carbon controls are put in place. After 2050, however, the study -- managed by the MIT Energy Initiative -- says that carbon-free fuel sources that include both renewables and nuclear power will assume the central leadership roles.

"In a carbon-constrained world, natural gas will become a larger part of the energy mix," says Ernest Moniz, director of the MIT initiative. "But in the longer term, it will be necessary to shift to 'essentially zero-carbon' sources so we better not get mesmerized by gas either. We need to do the hard work of getting those alternative technologies ready to take over."

The analysis assumes that policies would be in place to cut greenhouse gas emissions by 50 percent by 2050 and by 70 percent by 2070. The researchers are also saying that energy prices will rise by 30 percent by 2030 and by 45 percent by 2050. Those increases can be partially attributed to a price being placed on carbon.

Moniz cautions that diverting the nation's attention to natural gas should not mean neglecting nuclear development and carbon capture and storage technologies. With that in mind, he goes on to say that if natural gas starts replacing coal it would then make a noticeable dent in carbon emission levels. As such, highly efficient combined cycle natural gas plants could begin to replace to outdated coal plants. Natural gas emits half as many greenhouse gases as coal.

To that end, MIT says that natural gas facilities built in the mid 1990s are now underutilized with many operating at capacities of 41 percent. That could be doubled -- not just because those modern plants could handle the additional load but also because the nation has the gas resources available to it. The United States has about 92 years worth of recoverable natural gas in the group at current consumption levels. Globally, the MIT report says, 160 years worth of natural gas reserves exist.

The increase is because of shale, which is a sedimentary rock that is less porous than sandstone where traditional natural gas is found. While explorers have always known that such formations are filled with gas, it has only been in recent years that retrieving those resources has been technologically feasible. With horizontal drilling, producers can move laterally beneath cities and neighborhoods to extract the product.

The Proof

The U.S. Energy Information Administration is predicting that total domestic natural gas production will grow from 20.6 trillion cubic feet in 2008 to 23.3 trillion cubic feet in 2035, with shale accounting for a quarter of that expansion. But if this gas is to be recovered and delivered, the MIT study says that the infrastructure -- pipeline and storage -- must be widely expanded.

MIT's findings, along with the government projections, are supported in the marketplace. ExxonMobil bought XTO Energy for $31 billion. By betting on natural gas, the oil company is saying that fossil fuels will remain paramount but that tighter air quality restrictions are coming. Its own annual energy outlook anticipates natural gas to grow faster over the next 20 years than either oil or coal.

Meanwhile, Royal Dutch Shell made an offer in May to buy nearly $5 billion worth natural gas assets in Pennsylvania. The Marcellus Shale formation in that region is said to have enough natural gas to meet the country's needs for a decade or longer. Shell is also acquiring sizable acreage in southern Texas to access shale deposits there.

"The opportunity now is to consolidate our tight gas portfolio, divest from non-core positions across North America and to invest for profitable growth by deploying Shell's technologies and capabilities on a large scale," says Peter Voser, chief executive of Shell, referring to the shale gas acquisitions in Pennsylvania and Texas.

The question now posed to energy analysts is whether other oil giants will start bidding on the smaller producers that might need more financial muscle. Big Oil, which has found the regulatory process in this country less-than-friendly to production, has typically invested much of its resources harnessing overseas oil fields. Natural gas development, in this country, has pretty much been left to the less-noticeable players.

Substantially increasing natural gas production for power plant usage is likely to take a few decades. After 2050, though, the MIT scholars are saying that natural gas could give way to green energy forms, which over time, will become more and more cost effective as developers and suppliers perfect their techniques.

At that point, natural gas would "back up" those renewable generation sources to ensure reliability. To compete, natural gas-fired power plants would have to work toward capturing and burying their carbon emissions.

"(U)nder a policy based on emissions pricing to mitigate greenhouse gas emissions, natural gas is in a strong competitive position unless competing technologies are much less expensive than we now anticipate," says MIT's report.

As to whether natural gas becomes a bridge fuel until cleaner energy can be reliably and cost-effectively delivered is unknown. Gas producers are now tarred with the same brush as the oil giants. Coal interests, meanwhile, won't just surrender. But with the fundamentals now in place, natural gas developers are seeing a bright future.